code: def gpt_model(model_cfg, trainer_cfg, precision):
      model_cfg["precision"] = precision
      trainer_cfg["precision"] = precision
  
      strategy = NLPDDPStrategy()
  
      trainer = Trainer(strategy=strategy, **trainer_cfg)
  
      cfg = DictConfig(model_cfg)
  
      model = MegatronGPTModel(cfg=cfg, trainer=trainer)
  
      return model
  
file_path: NeMo/tests/collections/nlp/test_gpt_model.py
imports: import os
  import pytest
  import torch
  from omegaconf import DictConfig
  from pytorch_lightning import Trainer
  from nemo.collections.common.tokenizers.huggingface.auto_tokenizer import AutoTokenizer
  from nemo.collections.nlp.models.language_modeling.megatron_gpt_model import MegatronGPTModel
  from nemo.collections.nlp.modules.common.megatron.utils import get_ltor_masks_and_position_ids
  from nemo.collections.nlp.parts.nlp_overrides import NLPDDPStrategy
label_desc: Use image node_id 4 for calling a global function with example usage: gpt_model(model_cfg, trainer_cfg, precision) and returns: model